When current-carrying contacts in electrical switches are opened, electrical arcs are formed. For example, an arc is formed when current-carrying contacts open in the event of a short-circuit. Arcs cause burning of the contacts, which consist mainly of silver and are therefore expensive. If an electrical arc is not extinguished quickly enough, a great deal of energy flows through the protective device, the power cables and the devices that need to be protected. This leads to thermal overload and in some cases even to the destruction of current-carrying and adjacent parts of an electrical circuit.
To extinguish electrical arcs, extinguishing plates are typically used, which split the arc into a plurality of sections and cool it, so as to extinguish it faster overall. During the current flow of the arc, a magnetic field is generated which drives the arc in the direction of the extinguishing plates, where it is then extinguished.
Previously, extinguishing plates made from ferromagnetic materials have been used in order to accelerate the extinguishing process.